A forklift truck is used for lifting and laying down cargo or shifting cargo to a desired place within a limited space, which can be classified as an engine forklift truck and an electrical forklift truck depending on the power resources. Especially, an electrical forklift truck is operated by electricity supplied from a battery, which includes a drive motor for driving and a pump motor for hydraulic driving.
The drive motor is an electric motor driven by electricity. The electric motor generates high-temperature heat when being driven, and if the temperature of the motor and controller reaches the predetermined high temperature, the drive motor triggers a system shutdown to prevent components from being damaged due to dielectric break. Therefore, in order to restrain the increase of the temperature, a cooling apparatus, such as a cooling fan, is separately mounted on the motor and controller so as to extend the time of continuous operation of the electrical forklift truck.
However, there is a problem when the cooling apparatus is separately mounted for postponing the shutdown and extending the time of continuous operation in the conventional forklift truck, the energy is consumed for driving the cooling apparatus so as to decrease the effect of postponing the shutdown of the forklift truck, and additional cost is incurred for constructing the separate cooling apparatus.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.